Unresolved problem with vodacom

Horrible experience with vodacom firstly I’m a excellent payer and wouldn’t think I would go thru this I have a contract with vodacom and don’t have the phone for a year and found it jamming so I took it to vodacom to have it sorted out and mind you it’s still under warranty so they took it in and told me to come fetch it after a few days got there checked that it was fine to take back all was well got home and one day later found it’s doing the same problem so I took it back they sent it in agian for repairs and told me again I must come fetch it after 3 days went to pick it up again checked if it was ok then took it back home same problem occurred after 2 days so I went back to the shop n reported this continues problem and demanded that they replace this phone mind you I’m paying for something I can’t use they gave me a long story y they can’t replace it so they sent it again for repairs now this will be the fourth time I’m taking it back because I’m still experiencing the exact problem I’m sick n tired of gng out my way using my patrol to go up n down to the mall to sort this ongoing problem n I dnt c y they can’t replace this phone because it’s clear that it can’t be fixed